March 2019

CATARACT

Presentation spotlightThe 30-minute cataract

by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer

This figure shows that in cases with a topical or sub-Tenon’s anesthetic and no intraoperative complication, an increase in the cataract complexity score did not result in an increase in operating time, with the exception of high complexity scores.

This figure shows that the mean operating time (in uncomplicated, topical, or sub-Tenon’s cases) decreased by approximately
3 minutes among consultants with similar trends in trainee groups between 2012 and 2016. The findings of decreasing operating time among consultants who would not vary year on year supports the hypothesis that phacoemulsification cataract surgery is
becoming more time efficient.
Source: Paul Nderitu, MD

Study highlights the factors affecting cataract operating time among trainees and consultants

The high volume of cataract cases at surgical centers requires cataract surgery to be quick and efficient. According to a study presented at the 36th Congress of the European Society of Cataract and Refractive Surgeons (ESCRS), one-third of all cataract surgeries are now being done by trainees, leading to longer mean operating times and elevating the necessity for solid training and well-structured OR management. Assigning less complicated cases to trainees saves time and effort.
“At all levels, including junior trainees, the mean operating time for cataract surgery is up to 30 minutes in uncomplicated cataract cases. Highly complex cataract cases will modestly increase operating times, but fortunately, they are limited in occurrence,” said Paul Nderitu, MBChB, an intermediate fourth-year trainee in London, U.K., who reported the outcomes of a study he performed.

New study

Dr. Nderitu and Paul Ursell, consultant cataract surgeon, Epsom and St Helier NHS Trust, analyzed operation times in a study1 that combined electronic records from two databases from January 2011 to December 2016 for patients who had undergone primary cataract surgery performed by consultants and first- to sixth-year trainees. The cases involved standard phacoemulsification 2.0/2.2 mm and the implantation of injectable lenses. Patients who had combined procedures were excluded as were surgeries performed by surgeons who had performed less than 50 surgeries (<0.5% of the database).
Operating time was defined as the time between the patient entering and leaving the operating room, which included preoperative check, draping, phacoemulsification, IOL implantation, and undraping, omitting anesthesia and surgery setup time. “Our definition of operating time is time out of surgery minus the time into surgery, which captures the full event. The main variable is the phacoemulsification time, which is quite consistent with and particular to each individual surgeon. We looked at many other factors that can influence the operating time as well,” Dr. Nderitu said.
The study identified 11,067 cataract cases that fit the search criteria with operating times specified in 9,552 of them (86.3%), which were included in the analysis. Operating times reflected the surgeon’s experience, as expected. Dr. Nderitu found the mean times for cataract surgery to be:
• Consultant: 19 minutes
• First- to second-year trainees:
30 minutes
• Third- to fourth-year trainees:
27 minutes
• Fifth- to sixth-year trainees:
24 minutes
Dr. Nderitu and Mr. Ursell devised a comprehensive cataract surgery complexity score system for the selection of appropriate cases for trainees, using evidence based, validated risk factors for posterior capsule rupture, patient specific factors, and complexity stratification recommendations to minimize complications, optimize outcomes, and maximize patient safety. A complexity score of 0–1 signified low case complexity, 4–7 intermediate, 8–9 high, and ≥10 very high surgical complexity, which was seen less frequently. “We noticed that consultants’ operating times were fairly consistent until reaching very high scores before there was an increase in operating time. Three-quarters of patients fall within the low to intermediate scoring range while a patient with pseudoexfoliation, an only eye, or white cataract would fall in the high scoring range. Most of the high complexity cases were performed by consultants. Trainee operating times, although more variable as trainees rotated year by year, also remained fairly consistent with increases in operating times seen at scores ≥8,” Dr. Nderitu said.

Factors associated with operating times

Pupil size can slow down operating times, particularly among less experienced surgeons. “We looked at large pupils compared with small pupils and noted that even in our consultant group, there was an increase in the mean operating time in small pupil cases, which was expected,” Dr. Nderitu said. “For junior trainees in their first 2 years of training, we see a small decrease in operating time, probably because the consultant takes over and is able to complete it more quickly. There was a slightly higher operation time compared to consultants among the other, more experienced trainees who can do their own small pupil cases. In cases involving a pupil expanding ring, we observed about a 4-minute increase in operating time for consultants and 6 minutes for trainees.2 We noted a bigger increase in operating time in cases using iris hooks, which have to be put in individually, adding another mean 14 minutes to surgery for consultants and about 24 minutes for trainees. Capsular tension rings can add a mean 5 minutes to the surgical time.”
According to his data, the main complication that affected surgical time was posterior capsule rupture. “This can double your operating time regardless of who you are. But for consultants, starting at ~17 minutes of operating time, it can increase to 30 or 40 minutes, depending on the situation. When trainees are involved or helping to manage the complication, operation times can extend beyond 1 hour, which has also been published in the literature,” Dr. Nderitu said.
Temporal study data reveal a small decrease in individual consultant operating times from 21 minutes to 18 minutes over 5 years (2011–2016), including lower standard deviations, revealing an increase in efficacy through more highly standardized operative procedures. This fact is also reflected by the faster operating times seen among trainees, despite the fact that trainees only spend 1–2 years in this placement.
“Overall, I think what’s encouraging is that even the most junior trainees take 30 minutes to complete the whole procedure. In uncomplicated cases, we should not discourage juniors from operating. The cataract complexity score system is a useful tool for the stratification of case complexity and for the appropriate case selection to match trainee experience,” he said. “Cataract surgery is the most frequently performed elective operation in the U.K. with around 400,000 cataract procedures per year in England alone. There are limited data in the literature on the factors that influence or are associated with operating time in cataract surgery, which this study delineates. We need to continue to define these factors among trainees and consultants as well as the trends we see over time,” Dr. Nderitu said.